So your main priority is to continue on redirecting him from scratching/busting the sutures that are holding the surgical side together. Most of the cropped ears we see here do not have the silver nitrate and are generally bloody, scabby and tbh just look nasty, this is okay actually. You let the ears heal from inside out and let the scabs stay and do their job, which is to protect the tissues while they heal. I actually like the silver nitrate job your vet did and the posting job also, very proactive. You may have a very good vet there…not to knock on vets, but most are anti croppers and the ones that do crop greatly suck at after crop care and horrible at posting ears.
If you must clean the ears, most do. Get some warm water with just a little soap and wipe the ears gently with a warm soapy wash cloth- being careful not to tear, bust or pull scabs off. You can also get some qtips and clean in/out of the canal/crevices.
From here on…let the ears hang and be free until sutures come out. Just a lot of fun play to keep him happy and to you enjoy a precious puppy because very soon he will move into the Dobershark stage. The time of teething and being over rambunctious that will truly challenge you.
If you have not, read the puppy forum on this site and be ready with more redirection and initiation of training. With a 1yr old baby and a Doberman puppy, you are gonna have to figure out how to curb and drain your Dobermans energy. Lots of great info on this site that truly works. Just takes a lot of time and energy on your part.